The increased outdoor activities of many persons unfortunately causes an increased incidence of melanomas and skin cancers. Skin cancers are now the most common type of cancers in men and women in the United States, and are dramatically increasing each year. A primary care physician may excise several pre-cancerous or cancerous skin lesions per month.
A skin lesion smaller than 0.5 cm (0.20 inches) in diameter can be carefully removed by a physician using a scalpel or circular biopsy punch. The physician may then choose to either leave the wound open or to close it with a single suture. If a circular incision is used to remove a lesion that is greater than 0.5 cm in diameter, the subsequent suturing leaves a typical "smile-shaped" line with protruding ears, commonly called "Dog Ears".
To properly remove a lesion that is greater than 0.5 cm in diameter, a physician cuts an elliptical incision around the lesion, then sutures the two edges of the elliptical incision together. The result is a suture line which is straight and flat in appearance. This is the cosmetically preferred means for closing wounds from larger excised lesions. If the elliptical incision made by the physician, however, is too short and is proportioned more like a circle, the incision will also end up with "Dog Ears" when sutured. The ideal size ratio of length to width (major axis to minor axis) for the elliptical incision is 2.5 to 1.0 (2.5:1), however, other ratios up to 4.0 to 1.0 (4:1) could be used. This 2.5:1 ideal ratio holds true for all incisions that are greater than 0.5 cm (along the minor axis).
Some surgical devices presently available are capable of cutting a hole in a skin or other membrane surface. For example, U.S. Pat. No. 4,018,228 by Goosen discloses a surgical punch instrument that can create a hole in a hollow structure, such as the aorta or an eye. A small slit is cut in the aorta, for example, an outer blade is slid into the slit, then retracted against an inner blade, thereby cuffing a hole in the wall of the aorta. Another surgical appliance is disclosed in U.S. Pat. No. 4,716,901 by Jackson et al., which is a trocar that forms a hole in the skin so as to place appliances into a patient's body (e.g., drainage tubing). Two cutting edges are formed at opposite ends from a pair of hinged components, through which the trocar is inserted into a small skin opening when the tool is in its closed position. A rigid expander is then inserted near the hinges, causing the hinge components to separate, thereby expanding the slit in the skin. The appliance (i.e., the tubing) can then be inserted through the hollow expander.
Another surgical cutting instrument is disclosed in U.S. Pat. No. 2,521,161 by Grover, which acts as a meniscotome that cuts with a slicing action and allows removal of a meniscus. Another surgical instrument presently available is disclosed in U.S. Pat. No. 4,542,742 by Winkelman et al., and provides an elliptical cutting guide for skin lesion surgery. The Winkelman et al. disclosure describes the preferred ratio of the ellipse axes to be either 4 to 1 (4:1), or for larger wounds 3 to 1 (3:1). The elliptical guide is used as a template for the blade of a surgeon while excising a portion of skin.
None of the presently available surgical appliances is capable of creating an elliptically shaped, punched hole for use in removing skin lesions. Although the Winkelman et al. device can be used to assist in creating elliptically-shaped incisions, it has no means for actually creating the incision and requires the surgeon to use a scalpel or other surgical device to perform the actual cutting of the skin surface.